PROJECT SUMMARY BACKGROUND: Through application of existing knowledge, much of the cancer burden is preventable. State- level practitioners are in ideal positions to affect programs and policies related to cancer control. Mis- implementation refers to ending effective programs and policies or continuing ineffective ones. Greater attention to mis-implementation should lead to use of effective interventions and more efficient expenditure of resources, which in the long term, will lead to positive cancer outcomes. GOAL: This proposal seeks to describe the extent of cancer control mis-implementation and to identify leverage points for addressing mis-implementation in the United States. AIMS AND METHODS: This is a three-phase study that takes a comprehensive approach, leading to the elucidation of tactics for addressing mis-implementation. Phase 1: The first aim seeks to assess the extent to which mis-implementation is occurring among state cancer control programs in public health. This initial phase will involve a survey of 800 practitioners representing all states. The programs represented will span the full continuum of cancer control (from prevention to survivorship). Phase 2: Using data from Phase 1 to identify organizations in which mis-implementation is high or low, we will conduct eight comparative case studies to understand contextual differences. These case studies will highlight lessons learned about mis-implementation and identify hypothesized drivers. Phase 3: The 3rd aim seeks to build agent-based models to identify dynamic interactions between individual, organizational, and contextual (external) factors driving mis-implementation. Agent-based modeling will be used to determine the most effective potential approaches for reducing mis- implementation. We will translate and disseminate findings from Phases 1-3 to practitioners and practice- related stakeholders in order to support the reduction of mis-implementation. All study phases will rely on an Advisory Group of public health practitioners and close collaboration with key practice partners. INNOVATIONS AND IMPACT: This study is innovative and impactful because it will: 1) be the first to refine and further develop reliable and valid measures of mis-implementation of public health programs; 2) bring together a strong, transdisciplinary team with significant expertise in practice-based research; 3) use agent- based modeling to address cancer control implementation; and 4) use a participatory, evidence-based, stakeholder-driven approach that will identify key leverage points for addressing mis-implementation among state public health programs. This research is expected to result in a replicable model that can significantly impact mis-implementation in cancer control and can be applied to other health areas.